Radius Initiates Phase 2a Clinical Trial of RAD1901 in Menopausal Hot Flashes

--Study will evaluate proof of concept for company's first-in-class SERM
designed to relieve vasomotor symptoms without side effects associated with
hormone therapy--

CAMBRIDGE, Mass., March 24 /PRNewswire/ -- Radius Health ("Radius") announced
today that the first patient has been dosed in the company's proof-of-concept
Phase 2a study of RAD1901, an investigational selective estrogen receptor
modulator (SERM) undergoing clinical evaluation for treatment of vasomotor
symptoms (menopausal hot flashes). The clinical trial is designed to evaluate
the ability of RAD1901 to relieve menopausal hot flashes without the
administration of estrogen. RAD1901 has demonstrated positive effects in
preclinical models of vasomotor symptoms and a favorable safety profile in
Phase I human clinical studies.

"The initiation of this proof-of-concept trial is a significant milestone for
Radius," said C. Richard Lyttle, PhD, President and CEO of Radius. "A positive
outcome of this Phase 2a clinical trial would further position RAD1901 as a
next-generation SERM that provides an alternative to estrogen in alleviating
menopausal hot flashes, without the side effects associated with hormone
therapy. We look forward to reporting the results of this trial later in
2009."

"RAD1901 represents an ideal candidate for the potential treatment of
postmenopausal vasomotor symptoms, given its unique clinical profile
demonstrated in preclinical and Phase I studies--estrogen-agonist effects on
the central nervous system while protecting against breast and uterine tissue
stimulation," said Louis O'Dea, MD, Chief Medical Officer of Radius. "This
Phase 2 trial will provide us with critical insight into the dose-response
relationship between increasing doses of RAD1901 and efficacy in the treatment
of hot flashes."

Clinical Trial Details
The Phase 2a clinical trial, which is being conducted at approximately six
sites in Argentina, is a double-blind, placebo-controlled, dose-ranging study
in 100 otherwise healthy menopausal women experiencing recurrent
moderate-to-severe hot flashes who will be randomized to receive one of four
doses of RAD1901 and placebo. The duration of treatment after screening and
baseline will be 28 days. The primary endpoint of the study is the frequency
and severity of hot flashes relative to baseline. In addition, data on changes
in pharmacodynamic markers of estrogen effect--follicle-stimulating hormone
(FSH), luteinizing hormone (LH), and lipid profile effect--will be collected.

About RAD1901
RAD1901 is a novel selective estrogen receptor modulator (SERM) under
development at Radius as a new class of menopausal therapy. SERMs are small
molecules that bind to and selectively modulate estrogen receptors. These
molecules have the ability to stimulate or block estrogen's activity in
different types of tissue, functioning as estrogen receptor agonists in some
tissues and as estrogen receptor antagonists in others. Currently available
SERMS are approved for the treatment and prevention of breast cancer and
osteoporosis but tend to respectively increase the frequency and severity of
hot flashes. In preclinical studies, Radius demonstrated RAD1901's potential
to reduce vasomotor symptoms, along with a simultaneous bone-protective
effect, without stimulating breast or uterine tissues. RAD1901 is distinctive
from other SERMs in its unique biological profile, combined with its
significant ability to penetrate the blood-brain barrier, which enables
RAD1901 to function as an estrogen agonist within the central nervous system
and thereby relieve hot flashes. RAD1901 was discovered by Eisai Co., Ltd. and
licensed by Radius (excluding Japan) in 2006.

About Vasomotor Symptoms (Hot Flashes)
Hot flashes are a common symptom during menopause, experienced by more than
75% of women during the menopause transition for a median duration of four
years. These symptoms can disrupt sleep and interfere with quality of life. An
estimated 6,000 U.S. women reach menopause every day (more than two million
per year) with a total population of 50 million postmenopausal women. In
addition, most women receiving systemic therapy for breast cancer suffer hot
flashes, often with more severe or prolonged symptoms. Treatment with estrogen
or hormone replacement therapy (ERT or HRT) is the standard of care for many
women suffering hot flashes, but due to concerns about potentially serious
risks and contraindications, including increased risk of developing heart
disease, breast cancer, stroke, and dementia, there is a significant need for
new therapeutic options.

About Radius (www.radiuspharm.com)
Radius is a leading company in the discovery and development of a new
generation of drug therapies for osteoporosis and women's health. Radius has
raised $106.5 million in private equity financing since its establishment in
2003 and is based in Cambridge, Massachusetts.

Contact:
Nick Harvey
Chief Financial Officer
(617) 551-4704

SOURCE Radius Health

Nick Harvey, Chief Financial Officer of Radius Health, +1-617-551-4704